Reponses and sensitivities of maize phenology to climate change from 1981 to 2009 in Henan Province, China

With the global warming, crop phenological shifts in responses to climate change have become a hot research topic. Based on the long-term observed agro-meteorological phenological data (1981-2009) and meteorological data, we quantitatively analyzed temporal and spatial shifts in maize phenology and their sensitivities to key climate factors change using climate tendency rate and sensitivity analysis methods. Results indicated that the sowing date was significantly delayed and the delay tendency rate was 9.0 d center dot 10a(-1). But the stages from emergence to maturity occurred earlier (0.1 d center dot 10a(-1)< 1.7 d center dot 10a(-1), theta is the change slope of maize phenology). The length of vegetative period (VPL) (from emergence to tasseling) was shortened by 0.9 d center dot 10a(-1), while the length of generative period (GPL) (from tasseling to maturity) was lengthened by 1.7 d center dot 10a(-1). The growing season length (GSL) (from emergence to maturity) was lengthened by 0.4 d center dot 10a(-1). Correlation analysis indicated that maize phenology was significantly correlated with average temperature, precipitation, sunshine duration and growing degree days (GDD) (p < 0.01). Average temperature had significant negative correlation relationship, while precipitation, sunshine duration and growing degree days had significant positive correlations with maize phenology. Sensitivity analysis indicated that maize phenology showed different responses to variations in key climate factors, especially at different sites. The conclusions of this research could provide scientific supports for agricultural adaptation to climate change to address the global food security issue.